title: Directional magnetoelectric effects in MnWO4: magnetic sources of the electric polarization.
abstract: The ferroelectric order and magnetic field induced effects observed in the spiral phase of MnWO4 are described theoretically. It is demonstrated explicitly that the Dzyaloshinskii-Moriya antisymmetric interactions contribute to the correlation between spins and electric dipoles in the incommensurate and commensurate ferroelectric phases of magnetic multiferroics. However, other single-site symmetric interactions are shown to be involved in the magnetoelectric process, suggesting the possible existence of an electric polarization originating from purely symmetric effects.
authors.affiliation: Laboratory of Physics of Complex Systems, University of Picardie, 33 rue Saint-Leu, 80000 Amiens, France. pierre.toledano@wanadoo.fr
authors.forename: P
authors.initials: P
authors.lastname: Tolédano
authors.forename: B
authors.initials: B
authors.lastname: Mettout
authors.forename: W
authors.initials: W
authors.lastname: Schranz
authors.forename: G
authors.initials: G
authors.lastname: Krexner